Is the ab coaster any good? I think I am getting uneven obliques from them?

Is the ab coaster any good? I think I am getting uneven obliques from them?

Hey guys.

What do u guys think of the ab coaster? do you find it helpful at all?I have been doing it for 1 month now for my obliques and I feel that my right hand side obliquesfeel stronger than my left hand side 1's? I have a bit of spine problem where the right side of my backarches slightly more than my left side so I'm not sure if this has anything to do with it?